Installed Invidia Overpipe? Bad knocking in the front?
 

Just installed my Invidia overpipe and have a really bad knocking noise coming from the front on hard acceleration or start up? Any ideas?

Seems like this solution wouldnt be overlooked. But did you tighten all the bolts down? You may not have torqued one down enough and the vibration from the hard acceleration will cause a loose bolt to make that sound.

Yep I just installed the Skunk2 headers and double checked the torque on everything (motor mounts, flange bolts, etc)

It's like you can almost feel it when driving. I don't think it's suspension related and it's only coming from the passenger side right where the overpipe is

is the overpipe knocking against something?

sounds like overpipe hitting chassis, try removing ftont pipe bolt from mounting bracket then lift btacket so you can put the bolt UNDER the bracket not through the hole and tighten up, this will lift overpie a bit, it that works then drill a new mount hole in frontpipe bracket on car chassis and use nut\bolt with lock washer to mount front pipe

I was going to suggest using a small crow bar and bend that sucker away from whatever it looks like it may be hitting.

Too bad the world ran out of baling wire ..... :(

However, @steve99's suggestion sounds much more better ..... :D


humfrz

I tried your suggestion @steve99. It didnt seem to help at all? I looked at the overpipe while i had it up in the air and it doesnt look like it's touching the subframe. Any other ideas? Will i have to go back to stock overpipe?

It may not be touching the frame with the engine not running. However, when the engine is under load it may "torque over" just enough for the pipe to touch the frame.

I suggest you figure which way the engine torques under load, then get under there and try to pull the pipe in that direction, to see if you can get it to come close to the frame.

If so, it’s BFH, crowbar and/or bailing wire time…… :paddle:


humfrz

Yea F* That @humfrz . I don't wanna have to jerry rig a pipe onto my car. Can you please give me any input on one that doesn't have fitment issues?

Order perrin motor mounts. It stopped my 3" overpipe from hitting. My engine doesn't wiggle at all...

the engine will move on the mounts during hard acceleration and this usually results in downpipe moving downwards.

sometimes the overpipe hits the frint sway bay especially aftermarket thicker bars

also look if the header ar hitting on the alluminium splashguard or the secondary cat hitting on chassis

or you got a dud overpipe like this guy check yours against stock overpipe, or your header may be proplem even a slight offset or angle difference throws off overpipe allignment
http://www.ft86club.com/forums/showthread.php?t=59400


also see this thread few post down guy had same issue with invida overpipe see photos

http://www.ft86club.com/forums/showthread.php?t=91424

Of course, scooter, just put the stock pipe back on.


humfrz

@GsxrMe I might end up doing that.@steve99 I have a Invidia front pipe and wasn't knocking until I replaced the overpipe, even with the stock headers. I reinstalled the oem front pipe and still no good. Everything bolts up no problem, so I am guessing it's just the mounts. There is less than half and inch of clearance between the subframe and the bottom of the overpipe. @humfrz I'd really like to keep an aftermarket pipe on there. I am going to try the Perrin mounts and if that doesn't work I guess I'll just reinstall the OEM overpipe. I was wondering though, does the Perrin overpipe fit any better?

you reinstalled the dough nut type gasket at rear of front pipe?

alse it sounds like a out of tollerance overpipe

Well, now, @Jtbirchfield, let’s see if I have this straight.

You have a stock engine block, sitting on engine mounts, that give a bit, and hooked to that you have a aftermarket (Skunk2 header), which is hooked to an aftermarket (Invidia) overpipe, which is hooked to an aftermarket (Invidia) front pipe.

All this is jammed into a tight space and winds in and around other things.

In a perfect world, all would fit and nothing would bang against anything else.

It’s been my experience, in wrenching around and modifying automobile engines for the past 60 some years, that sometimes things need to be “tweaked” a bit in order to work/fit proper.

Thus, my recommendation is to bend, twist, push, wire over, whatever is not fitting quite right.

:)


humfrz

@steve99 I did not reinstall the doughnut gasket because I have a 3 inch Perrin catback on it which comes with a 3 inch flange gasket.

Mine knocks a little under acceleration, thinking about just heat wrapping it good so i doesn't hit hard.. Eventually upgrade my mounts... I'm FI too so the engine moves a good amount

Let me start by saying I'm turbocharged. Making the downpipe, over pipe, and front pipe meet without touching the frame required a bit of tweaking.

I'm reading what you posted, and let me quote it back to you a different way...

"Hey guys, so I bought cheap aftermarket exhaust parts, and I mixed and matched the brands... So, um, I'm not sure how to say this, but they don't match up perfectly and I think that's bullsh*t... So, I'm going to publicly dog on the brand names, and willfully make no attempt to fix it."

Doesn't that sound sh*tty? Of course they don't match up. Take the heat shield off of your stock overpipe. It isn't round. It has huge distortions and variations in diameter in order to make it fit with the heatshield.. It looks like somebody took a hammer to it. These aftermarket companies promise you a constant diameter mandrel-bent unit. They will necessarily deviate from the shape and fitment of the stock part. If you mix and match brands, you will almost assuredly have to deal with fitment issues. Especially in tight spaces. Especially with cheap parts. Period.

By the way Dublin, I hope you meant Dublin Ohio or Dublin California, because otherwise you're sitting on the right hand side... I don't mean to be a d*ck, I just get skeptical when a low-post-count user comes and beats on a product, making sure to mention the brand names loudly and often. I start to worry that I'm seeing false-flag vendor-bashing. It's happened in more than a few threads. I get more suspicious and less sympathetic when that user ignores advice and seems unwilling to try to fix the problem. I like Mr. Humfrz's suggestion. If you don't want a solution, why post a problem?

This is what I did when I installed my overpipe and it worked, doesn't touch the frame any longer.